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Isotech offers ISO/IEC 17025:2017 Accredited Calibration and NIST Traceable Calibration services from -196 to 1200C (2200F) for a variety of instruments such as SPRTs, RTDs, Thermistors, Thermocouples, Readouts, Liquid-in-Glass Thermometers, Dry Block Calibrators and Electronic TC & RTD Simulators. Our comprehensive thermocouple calibration services and thermometer calibration services have been used by top laboratories all over the world.

Our Calibration Certificates always include data, a list of standards used and ITS-90 or CVD temp co-efficients where appropriate. Certificates are compliant with the format and guidelines outlined by ISO/IEC 17025:2017.

We utilize both standard ITS-90 Fixed Point procedures and comparison techniques to offer a flexible solution depending on customer requirements. Our procedures are based on the technical information contained in NIST Technical Note 1265, Guidelines for Realizing the International Temperature Scale of 1990 (ITS-90) pertaining to secondary PRTs, and in BIPM's Techniques for Approximating the International Temperature Scale of 1990.

Isotech North America's facility in beautiful Colchester, Vermont is the distribution and service center for all the Americas (North, Central, & South America). We know our equipment better than anyone. If by chance you require thermometer calibration services, we can perform them at the same time without the additional cost of shipping to another facility.

For current laboratory lead times and pricing on our temperature calibration services based on your needs, give us a call (802) 863-8050, or email

You can view our Scope of Accreditation here, and our Certificate here.
View Isotech's Calibration Terms and Conditions

Best Measurement Uncertainties (k=2, 95% confidence)

Isotech Fixed Point Calibration Uncertainties

Parameter / Equipment Range Best Uncertainty () Comment
SPRT / PRT / Digital Thermometers -195.798C 3.7 mk (0.0037C) Liquid Nitrogen Comparison
SPRT / PRT / Digital Thermometers -38.834C 1.8 mk (0.0018C) Mercury Triple Point Cell
SPRT / PRT / Digital Thermometers 0.010C 0.7 mk (0.0007C) Water Triple Point Cell
SPRT / PRT / Digital Thermometers 29.764C 1.3 mk (0.0013C) Gallium Triple Point Cell
SPRT / PRT / Digital Thermometers 156.598C 2.7 mk (0.0027C) Indium Fixed Point Cell
SPRT / PRT / Digital Thermometers 231.928C 2.7 mk (0.0027C) Tin Fixed Point Cell
SPRT / PRT / Digital Thermometers 419.527C 2.9 mk (0.0029C) Zinc Fixed Point Cell
SPRT / PRT / Digital Thermometers 660.323C 6.5 mk (0.0065C) Aluminum Fixed Point Cell